int analogPin = A0; // potentiometer wiper (middle terminal) connected to analog pin 3
int potentiometerVal = 0;  // variable to store the value read
long light;
byte led = 12;

void setup() {
  Serial.begin(9600);
  pinMode(led, OUTPUT);
}

void loop() {
  potentiometerVal = analogRead(analogPin);
  light = map(potentiometerVal, 1024, 0, 0, 100);
  Serial.println(light);
  if (light < 20) {
    digitalWrite(led, HIGH);
  } else {
    digitalWrite(led, LOW);

  }
  
  delay(100);
}